Fact Sheet – Inclement Weather

For Immediate Release

Inclement weather, including thunderstorms, snowstorms, wind shear, icing and fog, creates potentially hazardous conditions in the nation’s airspace system. These conditions are, by far, the largest cause of flight delays. In an average year, inclement weather is the reason for nearly 70 percent of all delays.

CostDelays translate into real costs for the airlines and the flying public. Currently, the cost to an airline for an hour of delay ranges from about $1,400 to $4,500, with the value of passenger time ranging from $35 to $63 per hour. This means that delays cost the airlines and their passengers billions of dollars each year.

ChallengesEach kind of inclement weather presents challenges to the FAA’s air traffic control operation, but perhaps the most disruptive are the convective storms that strike in the summer. Winter storms, while potentially dangerous, often form and move slowly. By contrast, summer storms typically form, grow and move swiftly, covering large swaths of airspace. Many start in the Ohio Valley and move east, impacting air travel in the Northeast, particularly New York. Approximately one-third of all flights in the U.S. “touch” New York, flying to or from JFK, LaGuardia and Newark, connecting with those flights or transiting New York airspace, so severe weather impacting New York has a ripple down effect over the entire country.

SolutionFAA air traffic controllers can’t control Mother Nature, but they have a wide range of tools to mitigate Mother Nature’s impact on the flying public. These tools are used at the Agency’s Command Center in Warrenton, VA, which balances air traffic demand with system capacity on a nationwide scale, at Air Route Traffic Control Centers (ARTCC), which handle high altitude traffic, at Terminal Radar Approach Control (TRACON) facilities, which handle traffic around busy airports, and at airport towers.

These tools include ground stops, which keep aircraft on the ground when air traffic control is unable to safely accommodate additional aircraft in the system, ground delays, in which aircraft are delayed at their departure airport in order to manage demand and capacity at their arrival airport, and Severe Weather Avoidance Plans, whichminimize the impact of a large scale storm by easing traffic demand in portions of airspace impacted by the storm.

Other tools include the following:

Airspace Flow Program–identifies aircraft scheduled to fly through severe weather and provides new estimated departure times, giving airlines the flexibility to accept the delay, fly around the storm or cancel the flight.

Time Based Flow Managementis a technology used to adjust capacity and demand imbalances at select airports and points in the sky throughout the U.S., while Traffic Management Advisor is a comprehensive, automated tool for planning efficient flight trajectories from cruise altitude to the runway.

The way these different components connect, as well as their relationship within the airspace system, are shown in the high-level overview of NextGen Weather Architecture.

Looking to the future, the Weather Technology in the Cockpit (WTIC) Program is a NextGen weather research program designed to resolve gaps in cockpit weather information and technology, pilot knowledge and training, and pilot decision making in bad weather.

These are just some of the ways the FAA and its partners in the aviation industry work to help ensure passengers reach their destinations safely and on time.